Windows 7

New features

Double click resize part of border to maximize window vertically.

Drag a window till the cursor is in the middle of an edge of the
screen and the window will fill a portion of the screen

Sound > Playback > Set Default now takes effect immediately for
all apps instead of requiring you to restart an application that
was started when a different playback device was set as
default. Saves time if you use optical audio out on a laptop and
change playback device frequently.

Screen snipping tool, useful for looking at changes to a program's
output side-by-side